PhD defence: Evolutionarily conserved crosstalk in developmental biology

PLEASE NOTE: If a candidate gives a layman's talk, the livestream will start fifteen minutes earlier.

Cellular communication is a fundamental process in animal development and homeostasis. Signaling pathways are the basis of this communication, as the transduction of external and internal cues leads to a cellular response such as cell migration or division. Signaling pathways are often described as unidirectional, but it is important to appreciate that many signaling pathways also exhibit crosstalk, i.e. they interact with other signaling pathways to stimulate or inhibit each other. Although there are many examples of signaling pathway crosstalk, the mechanisms of action are not well understood. However, besides a deeper understanding of fundamental biological processes, knowledge on signaling pathway crosstalk is of significance for translational applications, because therapeutically interfering with a signaling pathway will affect the activity of other pathways as well.

This thesis investigates the crosstalk of evolutionarily conserved signaling pathways in central developmental processes. First, the role of the conserved Wnt signaling pathways during cell migration in the nematode C. elegans is explored. This reveals crosstalk between two Wnt signaling pathways that converge on a single protein to drive cell migration. Moreover, an example of crosstalk between the Wnt and Slit-Robo signaling pathways is described as well, as the expression of a Wnt-regulated gene is found to be required for the activation of the Slit-Robo pathway. Interestingly, this second crosstalk mechanism is conserved in the mammalian intestine. Finally, this thesis highlights that model system-specific research methodologies can be applied out of their original context as well. This crosstalk between research fields makes a case for the importance of interdisciplinary research.